Pups should be good ol' MMK45's which show up on ebay with surprising regularity it seems these days. That brass bridge is a far stickier wicket I'm affraid, although I do know that TonePros makes very nice replacement bridges that are an excellent quality. I have one in an x110 I picked up from JD awhile back and it plain rocks!

Best to check into the spacing before springing for one but I've never heard of one not working. As far as a comparison to a '59 I am not really a good one to comment on that. My experience with SD's is limited to BurstBuckers, Pearly Gates, DimeBuckers and Parallel Axis pups.

I can tell you that an MMK45 is an extremely versatile pup which has something of a chameleon-like quality to it depending on what guitar it has been put into. I have them in many several of my Electras and Westones and they really can do just about anything you would like for tone of you are willing to experiment long enough with them.

But why settle for my lame attempt to describe them when Mike can give you a brief demo...

One more nugget to share I just recalled Curdog. As with much of what Matsumoku produced the specs on the pups did a fair amount of evolving over the years as our favorite designer Mr. Tom Presley never rested on his laurels and continuously honed the edge of the capabilities of both the electronic and the pickups of his designs.

What I am getting at is that earlier versions of the MMK while indeed a mighty fine rock pickup improved in the later models of Electras and especially the Westones it was found in, more specifically in the latest Matsumoku built Westone Spectrums like the GT, LX and SX variants such as this one Mike is putting thru its paces here...

So if an authentic restoration of the pups is what you desire look for an earlier built pair. If an improvement is desired hunt down a later built pair, or even consider taking the time to find a pair of MMK53's or MMK61's... if you have the patience to search diligently for them they do pop up at times.

Do not get confused with him calling the pups UBC's as MMK pups go by different handles depending on which Matsumoku built badge they went into.

I'm fairly certain those are '45's in the 2236 you see him playing there. Egg on my face if I'm wrong.

The Flying Wedge has the Maxon pickups in it, and they're a bit high middy chainsaw sounding (to me!). Here's one of my fave videos, the X935 with MMK53's, which I can't really tell from a MMK45 to be honest with you, lots of different styles at your finger tips:

The MMK's are articulate and responsive, but if you play loud or overdriven, like I find myself doing often, they're gonna squeal because they're not waxed. If you like your Seymours, don't be too quick to change them out. You got a smokin' deal on that Ultima and that boost circuit looks cool. Best 'o luck, Mike.